Abstract: A glycoprotein which inhibits the growth of malignant cells or malignant tumors is obtained from animals and humans having malignant cells or tumors. The glycoprotein has a molecular weight of about 3600 and is a substrate for both the GT-I and GT-II isoenzymes of serum galactosyltransferase. The glycoprotein is isolated by subjecting a body fluid or extract of the malignant cells or tumors containing the protein to serial column separation steps with materials which concentrate glycoprotein and separate a fraction having a molecular weight of about 3600. The effective form of the glycoprotein as set forth herein is intended to include the glycoprotein as well as its physiologically and pharmacologically active metabolites in the body.

Abstract: Pure galactosyltransferase isoenzyme GT-II having a molecular weight of about 71,000 is obtained from malignant cells or tumors of animals and humans. The GT-II is isolated by subjecting a body fluid or extract of the malignant cells or tumors containing the isoenzyme and GT-I galactosyltransferase isoenzyme to serial column separation steps and utilizing materials in the column which resemble cofactors for galactosyltransferase GT-II.